DS was like this too. We kept offering the food to him, putting it on his plate, not making a big deal of it or forcing it and eventually he's started to try and enjoy more types of meats. He still has days where he doesn't like something that he liked yesterday (typical toddler!
), but it's much better. We resorted to using sauces here and there when he wasn't eating much (e.g. ketchup, mild bbq sauce, plum sauce), but have to watch it as these have a lot of sugar and we don't always get a good toothbrushing at bedtime!
Is she getting other sources of protein (beans, lentils, eggs, etc.)?